"Perhaps you should experiment with trying it yourself and record whether it is effective for you."

"...I also think I separately lack this talent for forgetfulness."

"Unfortunately, I cannot teach you, as I do not remember how I learned it."

"That's all right."

Anyway, assuming Daeran either decides to practice marching or get on the horse, they can go.

There are plenty of demons inside the Wardstone barrier, but most of them would rather teleport away than try their luck against a group of this size, and the ones too weak to teleport mostly aren't a big problem. 

As the sun is starting to set, they're passing through some particularly warped-looking hills when twelve rocks, each about half a foot across, pick themselves up off the ground and hurl themselves at Blai. Nine of them hit, slamming into him with enough force to leave him badly injured.

Who was that? And how did they know to go for the Knight-Commander in particular?

The Worldwound does not seem interested in answering this question for her!

One of the more experienced paladin-archers moves in closer to the Knight-Commander to be in range for a Paladin's Sacrifice if it's called for.

That's really weird? Do the rocks look to be otherwise magical? Are there more rocks than that of this kind around?

The rocks are not obviously magical to visual inspection, they look like normal rocks. There are more rock piles of similarly-sized rocks ahead and to their sides, positioned in a way that could be coincidence but under the circumstances probably isn't.

"Who has Detect Magic today?"

All his party's wizards have Detect Magic, but Nenio is fastest to the draw on actually casting it. It will take a couple moments before she can provide detailed information, but in the meantime she crouches down and stares at a rock so the only thing in the spell's area is the rock and the ground.

"I am sensing the presence of a magical aura!" she confirms.

"...yes, what kind?"

"Be patient, select boy, I am attempting to determine that."

Another pile of rocks is going to take advantage of this opportunity to go flying at Blai!

"Paladin's Sacrifice!"

The sacrificial paladin looks somewhat battered; Blai is not further injured.

Oh, perhaps he should lend the Knight-Commander some healing. He waves a hand lazily in his direction and casts a Cure Serious Wounds.

"Aha! I sense a very faint aura of transmutation on these rocks, consistent with the lingering effects of a spell that was recently cast but is no longer active. Considering their behavior, I suspect they may have been targeted by a Telekinesis spell."

"Okay, so someone is probably actively directing them and they're more likely to know how to be invisible than how to do Contingencies, let's see what we can find..."

Paladins with horses spread out, scanning the area with Detect Evil.

Thall and Ember send their respective familiars to fly straight up.

Nenio drops the Detect Magic and casts an Invisibility on select boy. 

More rocks go flying, this time targeting one of the paladin-riders.

The next-nearest paladin-rider wheels and turns towards them. "Over here, I see something—" 

(He's gesturing in the direction of a hill more than a hundred paces from where Blai was standing when the first rocks hit him.)

Well, it could be a giant or something. Does Blai see anything?

Not specifically. It's probably big enough to hide an ambusher, if the ambusher isn't too large.

"—It's gone," says the paladin.

"I don't like this, Chief. How'd they even know we were going to be here?"